Raphaël Duflos

Luc Froment, a reform-minded engineer, starts working at a steel mill in a small town. There he founds small groups of workers (and their families) under miserable conditions. Under the influence of Fourier's ideas, Froment tries to turn the mill into a workers' co-operative.

The film portrays the events on the day King Henri III of France arranged for Duke Henri de Guise to be murdered.